PS Q..pls ans with explanation

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by Brent@GMATPrepNow » Fri Jan 22, 2010 11:22 am
Inspired wrote:Each of the following equations has at least one solution EXCEPT

-2n = (-2)-n
2-n = (-2)n
2n = (-2)-n
(-2)n = -2n
(-2)-n = -2-n
Is there a typo here?
Looks like they all have at least one solution. Possible solutions are:
A. n=2
B. n=-2
C. n=-2/3
D. n=0
E. n=0
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by Brent@GMATPrepNow » Fri Jan 22, 2010 12:06 pm
Interesting.
When you select the quote option, you can see the question as it was entered, but once you review the post, several characters are changed.
The original question is:

Each of the following equations has at least one solution EXCEPT
-2n = (-2)-n
2-n = (-2)n
2n = (-2)-n
(-2)n = -2n
(-2)-n = -2-n
Last edited by Brent@GMATPrepNow on Fri Jan 22, 2010 2:40 pm, edited 1 time in total.
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by Inspired » Fri Jan 22, 2010 2:19 pm
Hi Brent,

the answer is given as first option

i.e

-2 power n = (-2) power -n

solution says in this scenario, both sides are not equal even when n = 0 because,

-2 power n = -1 * 2 power 0 = -1 * 1 = -1

(-2) power -n = (-2) power 0 = 1

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by harsh.champ » Wed Feb 03, 2010 2:09 am
Brent Hanneson wrote:Interesting.
When you select the quote option, you can see the question as it was entered, but once you review the post, several characters are changed.

]
On another thread also,i found a similar problem-https://www.beatthegmat.com/absolute-val ... tml#219747
I don't know what is the cause behind it but I think this is a matter of concern and should be immediately brought to the notice of BEAT THE GMAT TEAM.

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by papgust » Wed Feb 03, 2010 2:22 am
Hi harsh.champ,

That was posted 10 days back. Now this problem is not coming in this post as well. It is fixed across the whole system now.

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by harsh.champ » Wed Feb 03, 2010 2:37 am
papgust wrote:Hi harsh.champ,

That was posted 10 days back. Now this problem is not coming in this post as well. It is fixed across the whole system now.
____________
Hi papgust,

Thanks for notifying me.I am glad that the problem is fixed.
:):P:D